If two iPhones have the same Apple ID, they will essentially be sharing everything. This means that all calls, messages, photos, data, and other information will be synced between the two devices. While it is technically possible to sign into two different iPhones with the same Apple ID, it is not something that was intended or designed to be used this way.
One of the main issues you may encounter when using the same Apple ID on two iPhones is with the “calls on other devices” feature. This feature allows you to make and receive calls on multiple devices using the same Apple ID. However, if both iPhones are signed into the same Apple ID, it can cause confusion and issues with call forwarding. You may find that calls are being forwarded to both devices simultaneously, or that calls are not being properly forwarded at all.
Text message forwarding can also be affected when using the same Apple ID on two iPhones. Text message forwarding allows you to receive SMS messages on multiple devices, but if both iPhones are using the same Apple ID, you may find that messages are duplicated or not properly synced between the devices.
Another important consideration is that all photos taken on either iPhone will be automatically synced and shared between the devices. This can quickly fill up the storage on both devices, especially if you take a lot of photos. Additionally, any changes or edits made to photos on one device will be reflected on the other device as well.
Furthermore, having the same Apple ID on two iPhones can lead to confusion with app purchases and downloads. Any apps purchased or downloaded on one device will be automatically downloaded onto the other device, which may not be desired. It can also cause issues if both devices are trying to update the same app simultaneously.
In terms of data usage, having the same Apple ID on two iPhones means that both devices will be using the same iCloud storage. This can quickly fill up the available storage, especially if both devices are backing up photos, videos, and other data to iCloud.
While it is technically possible to sign into two different iPhones with the same Apple ID, it is not recommended or ideal. It can lead to confusion, issues with call forwarding and text message syncing, and problems with app purchases and storage. If you do choose to use the same Apple ID on two iPhones, it is important to be aware of these potential issues and take steps to mitigate them.